The present disclosure relates to computer graphics systems, and more particularly, to presenting images on a display.
One area of computing devices that has grown in recent years are gaming devices and virtual reality (VR) devices, which use a graphics processing unit (GPU) to render graphics from a computing device to a display device based on rendering instructions received from the computing device. In gaming devices, a scene produced on a display device can be oriented or modified based on user input (e.g., movement of an external controller to cause movement of the orientation of the scene, introduction of items into the scene, etc.). Similarly, in VR devices, the scene produced on a display device can be oriented or modified based on user input, where the input may include detecting movement of the user's head (e.g., detected movement of the VR device, such as a head mounted display (HMD)).
A common problem in the application of VR is the establishment of conditions which may promote motion sickness (also referred to as simulation sickness). Individuals may be susceptible to motion sickness in a virtual reality environment because their external view of the world is removed and entirely replaced by a simulated view influenced, but not entirely controlled, by the motion of the body. When the simulated view deviates from what the brain is expecting based on the stimulation of other senses (most notably the vestibular system), illness may result. As such, a user may have an uncomfortable experience while using VR devices when there is a difference in signals sent to the brain by the eyes and the inner ear. For instance, when the user is viewing a VR scene that includes motion, but the user is physically not moving, the difference in motion-related signals sent to the brain may cause the user to feel discomfort, nausea, fatigue, sweating, vertigo, or other motion sickness effects. Once begun, the motion sickness effects typically persist and even worsen until the disagreement between the visual input and signals from the inner ear are resolved.
Simulation sickness in virtual reality may be reduced or prevented by maximizing the accuracy of tracking head motion, maximizing the accuracy of predicting future motion, and minimizing the latency between the calculation of a head pose and the display of a virtual scene corresponding to the pose. When the simulated visual input closely matches the vestibular system physical input, motion sickness may no longer be a factor in virtual reality for a majority of users.
But restricting the view displayed in a virtual reality environment exclusively to the motion of the head may limit the freedom of movement traditionally provided by a simulation maintaining independent manual input controls, such as those found in video games with a first person view. By enforcing strict conformance to head motion, a user may be limited to the range of the physical space containing the VR system; which in turn may limit the range of experiences that may be provided through virtual reality.
For example, while video game simulations may commonly have users running miles across alien worlds while seated on the comfort of a couch and pressing the thumb-sticks of a gamepad, translating the same experience into virtual reality may not be possible when restricted to head motion alone, unless wearing a self-contained VR rig with miles of open space matching the terrain of the simulation.
Thus, there is a need in the art for improvements in presenting VR images on a display.